Exercise Rū Whenua 2024 commences today and will run over three days between now and mid-July.
It may have been an early wake up call for some just before 7am today.
Nearly 16,700 people have reported feeling the jolt.
The quake was at a depth of 65km.
The jolt, centred about five kilometres east of Christchurch, struck just after 5pm.
The earthquake was felt by thousands of people on GeoNet.
New Plymouth was rocked by three earthquakes in the space of five hours.
The quake hit at 9:30am, reported as having "strong" shaking, GeoNet says.
The group of divers are thrown side-to-side as the seabed begins to jolt.
